A deadly bomb in the capital confronts President Uribe with demands for results against the guerrillas

A GIANT Colombian flag, ten-storeys high, now drapes the façade of El Nogal, an exclusive social club in Bogotá. In the worst atrocity in Colombia's capital in more than a decade, a huge car bomb exploded in a parking garage inside the club on February 7th, killing 35 people and injuring 160. Even in a country inured to violence, grief and anger were widespread. Passers-by and office workers came to gaze at the shredded insides of the club, a supposedly well-protected haven for the city's rich. Officials blamed the FARC, Colombia's largest guerrilla army. Whoever did it, the bomb underlines the grim task facing President Álvaro Uribe, who took office last August.

Mr Uribe is pledged to crack down on the violent men of Colombia's two guerrilla armies, right-wing vigilantes and drug traffickers. He has begun an ambitious military build-up, decreed emergency security powers, and made a start on fiscal and political reforms. All this had begun to change the public mood. More people are travelling by road, thanks to better highway security. Officials claim to have foiled several bombings, and to have captured some culprits of previous attacks. When a bishop was kidnapped last year, the army quickly found and released him.

But public confidence remains fragile. An opinion poll last month gave the president an approval rating of 66%, down from 74% in November. And Mr Uribe has other problems. The bomb at El Nogal came the day after another big blow for the president. Juan Luis Londoño, his “superminister” for health and labour, a brilliant economist and capable reformer, was killed when the light aircraft taking him and three aides to a meeting in the provinces crashed into a remote Andean mountainside. Mr Londoño was responsible for pension and labour reforms that are vital to Mr Uribe's efforts to control Colombia's fiscal deficit while also improving defence and social provision. He will be hard to replace.

The immediate public demand facing the government is for results against the FARC. Over the past decade, thanks to money from the drug trade and kidnapping, the FARC has lost much of its previous communist ideology but has swollen to some 18,000 fighters. Until recently, it had remained a mainly rural, peasant force. Security analysts still doubt whether it possesses an urban support network robust enough to stage multiple attacks, but it can carry out sporadic terrorism.

In August, the FARC's urban militiamen killed 19 people in a misdirected mortar attack on Mr Uribe's inauguration ceremony. In December, a letter-bomb injured a senator closely allied to the president, and several dozen people were hurt by a bomb in a restaurant. Officials believe that outsiders have helped the FARC with explosives technology: three alleged members of the Irish Republican Army are on trial in Bogotá charged with giving the FARC training.

So far, Mr Uribe's main security innovation is an attempt to impose the state's control over two of the guerrillas' rural strongholds. These have been declared “rehabilitation and security zones”, in which the armed forces have been granted temporary extra powers by decree.

In one of these areas, the oil-rich province of Arauca, some residents say that life is now more peaceful. Arrests of guerrilla suspects have soared, after the government began to fly in prosecutors for short tours of duty. Officials say this has cut the number of attacks on Colombia's main oil pipeline: it was blown up 170 times in 2001, but fewer than 40 times last year. Mr Uribe has also stopped the payment of oil royalties to Arauca's local governments. These were routinely diverted to the guerrillas. They are now to be administered from Bogotá.

But rebel forces—right-wing paramilitaries as well as guerrillas—remain active in Arauca. Hostages are said to have been forced to drive cars packed with explosives towards military targets. This week, the ELN, the FARC's smaller cousin, ordered road and air transport in Arauca to halt.

Mr Uribe is expected to ask Congress for further, permanent, counter-terrorism powers. The El Nogal bomb will ease his quest. He also seeks more help from outsiders. The United States already gives Colombia some $500m a year in aid, most of it military; last month, 70 American special-forces troops arrived in Arauca to train a new army battalion. This week, the defence minister made a long-planned visit to Washington, seeking intelligence help. And six Central American presidents, meeting Mr Uribe in Panama, offered to co-operate against “terrorist violence”.

By attacking the cities, and especially politicians and the rich, the FARC's leaders seem to reckon that they can weaken both the economy and public support for Mr Uribe, thus bombing him to the negotiating table. They have offered talks about swapping guerrilla prisoners for scores of politicians and troops they hold as hostages, including Ingrid Betancourt, a former presidential candidate—but only if the government withdraws troops from a swathe of the countryside. Mr Uribe rejects this. Most Colombians reckon he is right to do so. But they would like to see some tangible results from the government's security policies, such as the capture of FARC leaders. Otherwise, they may start losing faith.